scripts/Makefile.asm-generic has the following comment: include/asm-generic contains a lot of files that are used verbatim by several architectures. This Makefile reads the file arch/$(SRCARCH)/include/(uapi/)/asm/Kbuild and for each file listed in this file with generic-y creates a small wrapper file in arch/$(SRCARCH)/include/generated/(uapi/)/asm.